In HTML+CSS+JS world, http://jsfiddle.net/ is very helpful tool for asking / making example about web development. And I also saw several browser(javascript)-based programming language compilers and REPLs. But I can't find online / web-based test environment for database operations( especially for RDBMS ).
Is there any open/free database service with web-based interfaces for testing queries?
Added: This tool will be good for this situation; If I'm troubling with complex queries, then create a sample table via web interface and ask it on stackoverflow with the 'sample table URL'. Anyone can access to the URL and test their queries on web site. (Yes, queries are running on 'real' database system) And also the query results can be tracked, then we can even make 'ranking' for it :)
Try SQL Fiddle.
You can try your SQL query and execute/test it.
There are free "disposable" database servers like db4free and even MonoQL.
As far as the web-based interfaces and short URLs go, I don't think you'll have much luck.
To manage your data you have to stick to what is provided (usually phpMyAdmin or similar) and there is no short-URL to query mapping. One other caveat of such system is that (without the appropriate user permissions) one user could easily destroy all your test data -- and remember that (relational) database versioning is much more expensive than plain text versioning, so that's pretty much out of the question.
For non-RDBMS, I can think of try.mongodb.org -- but it suffers from the same problems.
Almost forgot, the Stack Exchange Data Explorer, lets you practice T-SQL queries (with permalinks).
PS: As a personal side-note, I think it's a cool idea and I would love to see something like that implemented, perhaps even mashed-up with SchemaBank or similar - that would be just awesome.
You can't really test a query without the right underlying dbms, schemas (or databases), tables, constraints, stored procedures, and permissions, which tend to be highly application specific. (That is, not readily reusable among multiple users.)
Instead, the database world has grown up into database management systems that you can freely download and install locally. Then you can build and populate your own tables, and test your queries however you like.
Most of these come with both a command line interface and some kind of graphical interface. It's not clear to me what a web-based interface would give you that doesn't already exist in one form or another.
I think that, to do what you want, would require commercial licenses for Oracle, DB2, SQL Server, and Sybase. That's a pretty high barrier to entry for a free web site.
Trouble with a web based query analyser is that you'd need to let it 'tunnel' on to your box to run the queries and for many making a development/test box open to the internet is not a possibility.
For a non web based tool you could look at LinqPad http://www.linqpad.net/ - it does Linq & Sql and other stuff too - very handy tool indeed
Related
In my CS program, I was told I should learn SQL for my databases.
If I'm using PostgreSQL, do I also need a SQL server to go along with it? Is PostgreSQL a language, a server, or both? Is there even a SQL language or is it only servers?
Background: I downloaded Postgres because hey, that has SQL in the name, it works and I'm under the impression it's a pretty good choice anyway. But I couldn't figure out through their website if it needs a companion server, so I went looking for one and found AWS RDS.
The impression I have is that Postgres is the language and AWS RDS is the server, and they serve different functions. But I'm not sure about any of that.
Seems you're learning too many new topics at the same time.
Ok. I'll try to answer.
SQL stands for 'Structured Query Language', and serves as a 'standard' for many vendors that in much ways respects its fundamentals. Oracle, MySQL (now owned by Oracle), MariaDB and PostreSQL are some vendors.
Main thing with SQL code I would recommend you to identify every time you look at it, is to understand if it belongs to DML or DDL. DML stands for 'Data Manipulation Language' and refers to SQL instructions which 'modifies' data. DDL stands for 'Data Declaration Language' which defines or 'alter' de structure on which data will be stored.
Another important concept is atomicity of data manipulation. You can confirm a change or roll it back before it is persisted. This thing corresponds to 'commit' changes or do a 'rollback'. It's some kind of advanced concept, but generally happens "automatically" with standard client configurations. Later, you would have to know about it while programming some system module which interacts with databases.
When you think of the SQL 'server', it refers to the software configured/installed which has the responsability of manage persistence of data within some kind of 'instance' of persistence, allocated in some system with data storage capabilities. AWS implements this service in the cloud, and RDS is the product which supports many kind of SQL flavors to choose (Oracle, Postgresql, etc.)
If you are comfortable with Docker, I recomend you learn the basics which would help you setup and destroy databases many times, which is useful to develop and test locally. Next command, let you start a Postgresql database configured with open port 5432. You can see the server log through docker and use some SQL client to get connected. When you press Ctrl+C everything will be deleted. Of course there are other ways to keep data persistent, but this command would be an easy starting point.
$ docker run --rm -p 5432:5432 --name some-postgres-container-name -e POSTGRES_PASSWORD=mysecretpassword postgres:13.3
Side note: it's better to get used to work with specific docker image versions always (not 'latest').
More details of it usage here: https://hub.docker.com/_/postgres/
if I'm using PostgreSQL, do I also need a SQL server to go along with
it? Is PostgreSQL a language, a server, or both? Is there even a SQL
language or is it only servers lol? I'm genuinely trying to figure
this out myself, but basically everything I read is beyond my scope of
competence and confuses me more. I'm learning the syntax of SQL well
enough, but I'm so confused about everything on the most fundamental
level.
By the way "SQL Server" is Microsoft's SQL flavor, just another one. Don't be confused with the concept of having some SQL server configured.
Yes, you can think of PostgreSQL as a language too, which shares most of its syntax and semantics with other SQL vendors. Yes, there is a 'basic' SQL language shared and compatible between all vendors; some share more aspects than others. In terms of Venn diagrams, you can think of many circles representing each one, Microsoft's SQL Server, Oracle SQL, PostgreSQL, MySQL, etc. sharing the very most of its elements, where each element is a SQL instruction.
When dealing with Databases in general, keep in mind that they helps to modelate situations of 'real world' scenarios or software systems. SQL allows to 'talk' to implementation of "Relational Databases" wich is one kind of database modeling, but there are others too. ER Diagrams helps to represent the 'structure' of a database in a conceptual manner. I like DBeaver because it has an integrated ER diagram generator wich helps to understand the structure of a given database instance.
I have used Postgres and it is an excellent product (and free).
I would install it standalone first. It does come with its own client tools, which you use to communicate with the database server, which runs independently as a service. However, you might be better off installing something like SqlWorkbench as a client tool (which I use). In the config you specify the machine Postgres is running on (which can be your local computer for testing purposes) and the port to connect on. Essentially, the client sends your instructions to Postgres server and the server returns the resultsets associated with your instructions. The client also formats the resultsets into a nice readable "spreadsheet" format with rows and columns.
First I'll try to answer the questions you asked. There is a SQL language, but in practice it is not strictly standardized. There are many offerings for databases and database servers. Many of these are discussed below.
Any database you pick will give you the chance to learn basics of SQL queries and this knowledge will serve you well even if you switch to a different database later.
Specifically, when it comes to PostgreSQL, it is a Relational Database Management System. It is a software that operates as a server. You can install it on your personal computer running Windows, Linux, or MacOS. You can also install in on a dedicated server computer where you'll get better performance and uptime. Further, there are many companies that offer PostgreSQL hosting including Amazon RDS and Google Cloud but they're not free.
For a CS student, PostreSQL installed on your personal computer might be a reasonable choice. But you have lots of options. Read on....
For a CS program, your choice of database will depend on:
what degree of portability you need
how much data you have
how many users will connect to database
what kinds of jobs you might pursue after graduation
Portability
If you think you want to ship your database with your application, then your best bet is probably SQLite. By some accounts it can handle several million rows worth of data and still be performant. However, it's not great if you need for multiple users to connect to the same database. Your data can get corrupted in many multi-user scenarios.
How Much Data and Users
For large data and large users, you'll want to consider the client/server heavy hitters:
PostgreSQL
MySQL/MariaDB
Oracle
SQL Server
These databases will support large quantities of data any many simultaneous connections. But if you want to distribute the database with your application, it's not a good idea. Or if you want to demonstrate your app, you need to ensure that a connection to a server will be available. All of these databases come with a free version, but the last two will have the most restrictions.
After Graduation
Now you're looking to the future and possibly what kind of skills you want to put on your resume. If you think you'll end up in a corporate environment that is already well established, they will likely already have a preferred database and it could be any of the ones listed here (SQLite or the "heavy hitters"). If you want to position yourself as developing apps with low overhead cost, you'll gravitate towards SQLite/PostgreSQL/MySQL. If you think you're going to be some kind of database administrator working in a buttoned-up corporate environment, those companies tend to favor SQL Server and Oracle.
Good luck. Any choice you make will probably be fine. Knowing some flavor of SQL is useful for your future endeavors.
SQL is a language like any other language but working on database. It is called SQL because it works on structured data like table (i.e rows and columns). After reading the documentation of PostgreSQL, I think we do not need any separate server installation. You can download it from here. If you are facing any issues with it I suggest using MySQL workbench. Although installation may take longer time, but its easy to understand.
Just a bit of background on where my question is coming from: my company has multiple databases across the globe that uses the same schema and once of my department's responsibility is to monitor and make sure all these DBs are in sync from a schema SQL change perspective.
Now, my question is if anyone knows of any Software/tool that has a a Frontend UI which is able to do the following (the lower number the more important to have):
Able to track what SQL code change was applied on which database and when. Basically, if we write a SQL query that changed the structure of a table and we need it applied to 80% or 100% percent of the DBs, either via manual input or some automatic check the tool will tell me that yes, this was indeed applied.
Code distribution tool: we give it the query or a file that contains the code and it's able to push to the Databases it needs to (and create the audit log for that)
Code/object repository: keeps track of what was custom developed and pushed to the databases
I know SSIS might be able to do some of these things, but we need a tool that also has a simple frontend interface that can be accessed by non-IT personnel. (*clarification: we are not planning on giving non-DBA people access to change things, just to the audit aspect of said tool)
I've tried searching the internet, but i have a feeling i'm not using the right vocabulary to get the results i'm looking for.
Hence i wanted to see if the community was aware of any such tool or something similar?
Try searching for one of these two types of systems:
Release/Build/Deployment Automation Complex programs like Serena that have modules for pushing, tracking, and auditing any kind of software, anywhere. These will include all the GUI bells and whistles. But you'll have to deal with extra databases, configuration, agents, workflows, consultants(?), etc. These programs are geared more towards developers.
Remote Execution/Configuration Management Simpler programs like Salt, Fabric, and Ansible that let you run operating system commands anywhere. They don't offer as many features, and you have to do more of the work yourself, but in some ways that's liberating. If you know exactly what commands you want to run you don't need some other program holding your hand. These programs are geared more towards administrators.
From a database administrator's point of view, the main problem with those types of programs is that none of them are relational. Yes they can connect to a database and run a script, but none of them really speak SQL. Their native languages are Java, XML, SSH, etc. There's nothing wrong with those technologies, but if you only care about databases you don't want to deal with all that complexity.
If you're not happy with either of those types of programs I recommend you look at my open source program Method5. It is a remote execution program built as an extension to Oracle SQL. It works entirely inside an Oracle database, so you can install it yourself and won't need any additional websites, agents, configuration files, GUIs, etc.
Based on your comment about getting bogged down by links, and my answer to your question about half a year ago, I think this is the kind of program you were gradually heading towards creating. It took my team a couple thousand hours of developing and testing to get it right so you were probably wise to give up on making your own.
To specifically answer your requirements:
Tracking Changes are stored in an audit trail. But more importantly it has the ability and a pre-built script to compare an unlimited number of schemas, all in one view. At the end of the day what you really want to know is "are my schemas the same", not necessarily "did the same thing get run everywhere?".
Code Distribution If you just have SQL or PL/SQL, deploying it through Method5 is as easy as it can possibly get. Just specify what you want to run, and where you want to run it, like this: select * from table(m5('create index ...', 'dev, qa, prodDB1, prodDB2')); The program does not (yet) run SQL*Plus scripts. But when you have the ability to run SQL and PL/SQL so easily there's little need for SQL*Plus.
Code Repository All executions are stored in a simple table, M5_AUDIT. It contains the code, who ran it, where they ran it, and how they ran it. It wasn't designed to be a repository like SVN but it's good enough for simple auditing and tracking code.
Method5 does not contain a GUI but in some ways I consider that to be a feature. Since everything is done relationally, everything is in a simple table. You can use any of your existing GUIs - Toad, PL/SQL Developer, Excel, Apex, etc. It's a robust back-end solution that will hopefully make a good foundation for easily building a simple front end.
well I need some suggestion from someone who already know what type of database for my application is the best.
I have tried to play with My.Settings type stored data and also MS-Access.
But I was wondering if I will made some Password manager app, and if my database will be installed in C drive of user, if someone will find the database, he could easy open it and see all passwords and datas,
Thank you for suggestion as I really need some help on this question.
I believe the answer here is "it depends"!
All databases have their advantages and disadvantages. The rule that applies here is that depending on the use you want to do, choose respectively.
The strengths of MySQL for example is low cost (free if you ever need community support), the ability to run on any platform but also significant flexibility in remote management.
The MS SQL is also very stable, provides storage processes, transactions and other powerful features. However less cost and simplicity of management with respect to MySQL. Of course Express Edition is a good and sufficient solution for many circumstances.
If you would like a more specific suggestion you must provide us with some more information and features for the application you want to develop.
I'm using the file database SQLite, with SQLite Studio (for Free) and it's great staff, if you don't need robust data storage solution.
Here are some recommendations, how to set password:
Password Protect a SQLite DB. Is it possible?
Pluses:
common SQL,
single file,
simple according to my mind.
and many more.
Database should be password protected
Use Encrypting Strategy to save password
May be below article help you
http://msdn.microsoft.com/en-us/library/ms172831.aspx
The dev tools for SQL in Visual Studio are great.
Is it possible to develop an app for Microsoft SQL Server, and then deploy a MySQL-compatible database instead?
The dev tools for Microsoft SQL Server are really nice (i.e. LINQ support), but a MySQL-compatible column database has better performance for huge datasets.
You would need to use MySql .net connector
http://dev.mysql.com/doc/refman/5.1/en/connector-net.html
With this, you get some of the functionality that you have with SQL server (entity framework, designer, etc) there are still a bunch of things that are not supported, but it's a good start
It's possible, but a number of specifics might tend to prevent a full implementation on SQL Server, particularly with respect to stored procedures.
However, if the intent is to build a scaffolding on VisStudio and finish the development using the MySQL tools, it would work okay. You'll have to learn both SQLs quite thoroughly. The sooner you do that, the less grief there will be in the conversion.
One method for doing this would be to abstract away the database itself. That be done at least a couple of ways; the first way, you could use classes to build the SQL that your application requires, and then just use that; then all that has to happen is that it has to know how to generate the right SQL for the right server. One of the drawbacks of doing it that way, though, is that if you depend on functionality that exists on only one DBMS, you'll have to emulate it in that abstraction layer.
The other method that you could use is to create two versions of your classes that talk to the RDBMS, one for MySQL and one for Microsoft's SQL Server. Use an interface and derive from it in order to do the actual implementation. Of course, you'll want to make sure that the only responsibility of the class is to interact with the database, so if you're doing this for business layer objects, you'll be implementing those sorts of things with two classes: a low-level one for the database API, and a high-level one for actually providing the API that your application is going to consume.
Perhaps not a direct answer to your question, but the dblinq project may be of use to you.
It may be worth a look just to see the MySQL implementations within the project in order to determine what the real differences between SQL Server and MySQL are going to be and how they're going to affect you. The more you can abstract out those differences behind a dependency implementation, the easier it'll be to swap out one implementation for another.
You can write your code for SQL Server and then switch to Devart LinqConnect.
For example, you can create a LINQ to SQL model using Entity Developer (in VS integration mode or in standalone mode), then change the connection to the MySQL-specific one and run Update Database from Model wizard (don't forget to select the Regenerate Storage check box).
As a result, you will obtain a MySQL database, having structure identical to the SQL Server one.
When developing whether its Web or Desktop at which point should a developer switch from SQLite, MySQL, MS SQL, etc
It depends on what you are doing. You might switch if:
You need more scalability or better performance - say from SQLite to SQL Server or Oracle.
You need access to more specific datatypes.
You need to support a customer that only runs a particular database.
You need better DBA tools.
Your application is using a different platform where your database no longer runs, or it's libraries do not run.
You have the ability/time/budget to actually make the change. Depending on the situation, the migration could be a bigger project than everything in the project up to that point. Migrations like these are great places to introduce inconsistencies, or to lose data, so a lot of care is required.
There are many more reasons for switching and it all depends on your requirements and the attributes of the databases.
You should switch databases at milestone 2.3433, 3ps prior to the left branch of dendrite 8,151,215.
You should switch databases when you have a reason to do so, would be my advice. If your existing database is performing to your expectations, supports the load that is being placed on it by your production systems, has the features you require in your applications and you aren't bored with it, why change? However, if you find your application isn't scaling, or you are designing an application that has high load or scalability requirements and your research tells you your current database platform is weak in that area, or, as was already mentioned, you need some spatial analysis or feature that a particular database has, well there you go.
Another consideration might be taking up the use of a database agnostic ORM tool that can allow you to experiment freely with different database platforms with a simple configuration setting. That was the trigger for us to consider trying out something new in the DB department. If our application can handle any DB the ORM can handle, why pay licensing fees on a commercial database when an open source DB works just as well for the levels of performance we require?
The bottom line, though, is that with databases or any other technology, I think there are no "business rules" that will tell you when it is time to switch - your scenario will tell you it is time to switch because something in your solution won't be quite right, and if you aren't at that point, no need to change.
BrianLy hit the nail on the head, but I'd also add that you may end up using different databases at different levels of development. It's not uncommon for developers to use SQLite on their workstation when they're coding against their personal development server, and then have the staging and/or production sites using a different database tool.
Of course, if you're using extensions or capabilities specific to a certain database tool (say, PostGIS in PostGreSQL), then obviously that wouldn't work.